Answer:
The time at maximum height is 2.49 s.
Step-by-step explanation:
The time (t) at the maximum height can be found using the following equation:
![v_(f) = v_(0) - gt](https://img.qammunity.org/2022/formulas/physics/college/63kysg45z79ih2m7xmp1eymtmeajo07db8.png)
Where:
: is the final velocity = 0 (at the maximum height)
: is the initial velocity = 80 ft/s
g: is the gravity = 9.81 m/s²
Hence, the time is:
![t = (v_(0))/(g) = (80 (ft)/(s)*(1 m)/(3.281 ft))/(9.81 m/s^(2)) = 2.49 s](https://img.qammunity.org/2022/formulas/physics/college/pj7x9vihljc207z00623rirolkeyqj4w2m.png)
Therefore, the time at maximum height is 2.49 s.
I hope it helps you!